The present invention relates to an adhesive-forming product. More particularly, it relates to an effervescent article of manufacture which, when mixed with water, is suitable for use as a holding adhesive, especially as a wall covering adhesive. The wall coverings for which this invention are especially suited are wall papers, including the vinyl-coated and fabric-backed varieties. Other sheet materials for which the adhesive-forming composition are useful include paper, cardboard, fabric and the like.
Adhesive products for adhering these types of wall coverings have classically been formulated from such natural sources as starch, dextrin, gum arabic, gum tragacanth and certain modified casein or other animal protein bases. Most are dispersed as powders in water and develop, after application, their strength by drying. In recent years such adhesive products have been formulated with synthetic polymers to provide enhanced water resistance.
Adhesive products suitable for use as wall covering adhesives are designated as holding adhesives, i.e., adhesives that are intended primarily for merely attaching one adherent to another and holding it in place without requiring any significant resistance to external stressing. The working properties of such a holding adhesive product include characteristics that influence application, such as mixing, spreading, pressing, curing, speed of curing or rate of strength development and convenience of cleaning up afterwards. Heretofore, commonly available wall covering adhesive products have been messy and inconvenient to formulate and clean up. The packages of dry powder wall covering adhesive products commonly sold afford batches of a wall covering adhesive sufficient to paste an average size room. Scaling down to a smaller batch of the adhesive involves measuring the contents of the package, deciding how much is needed, and then mixing the required amount of dry powder with the proper amount of solvent. Thus, a worker requiring only a small amount of the adhesive usually wastes a substantial amount of the adhesive by premixing the entire package in order to avoid this bothersome procedure. Available dry powder adhesive products (which are non-effervescent in nature) also suffer from the disadvantage that they are inconvenient to mix in either small or large batches due to the lumping, caking and stickiness that are characteristic of the resultant mixture of dry powder and water. Preparing a lump-free paste mixture often involves portionwise addition of the dry powder to the volume of water coupled with vigorous and continuous stirring.